F 150 2WD Pickup V8-4.6L (2002)
Brake Light Switch: Description and Operation
Brake Pressure Applied Brake Deactivator Switch
Brake Pressure Applied Brake Deactivator Switch
The Brake Pressure Applied (BPA) switch also sometimes called the brake deactivator switch for vehicle speed control deactivation. Is a normally
closed switch, witch supplies battery positive voltage (B+) to the PCM when the brake pedal is NOT applied. When the brake pedal is depressed, the
normally closed switch will open and power is removed from the PCM.
On some applications the normally closed BPA switch along with the normally open brake pedal position (BPP) switch are used for a brake rationality
test within the PCM. The PCM misfire monitor profile learn function can be disable if a brake switch failure occurs. If one or both brake pedal inputs
to the PCM did not change states when they were expected to a diagnostic trouble code P1572 can be set by the PCM strategy.
